In modern electronic devices and systems, many signals are conveyed between various functional units, as well as to external devices/systems. The various signals may include data signals, clock signals, radio signals, and so forth. The frequencies of such signals may vary with respect to one another.
Often times during the operation of such a device, the frequencies of various signals may be deliberately changed during operation. For example, the frequency of a given clock signal may be reduced in order to minimize power consumption, or may alternatively be increased to boost performance. In another example, many wireless communications devices may use a technique known as frequency hopping spread spectrum (FHSS), in which the frequency of a radio carrier signal is periodically changed. Periodically changing the frequency of a radio carrier signal may randomize, and therefore reduce interference from outside sources.
Since the electronic system and devices referred to above are arranged for signal transmissions and receptions at a number of different (and varying) frequencies, circuitry may be implemented to manage the frequencies of at least some of these signals.